en COVID-19 infection in a patient with multiple sclerosis treated with fingolimod By nn.neurology.org Published On :: 2020-05-05T12:45:12-07:00 In December 2019, a novel coronavirus causing an infectious respiratory disease (COVID-19) was identified, which since then has developed into a pandemic with higher rates of mortality in older individuals and those with underlying medical conditions.1 Multiple sclerosis (MS) is an immune-mediated neurologic disease which requires long-term treatment with immunotherapies that have been shown to increase the risk of infections.2 As a result, there is significant anxiety among patients and neurologists during the pandemic regarding the infection outcome in this patient population. We present a patient with MS treated with fingolimod who was diagnosed with COVID-19 and had a favorable outcome. Full Article
en Neurologic syndromes related to anti-GAD65: Clinical and serologic response to treatment By nn.neurology.org Published On :: 2020-04-15T14:12:14-07:00 In the article "Neurologic syndromes related to anti-GAD65: Clinical and serologic response to treatment" by Muñoz-Lopetegi et al.,1 published online March 2, 2020, the y-axis label for figure 5’s right graph should be "CSF anti-GAD65 concentration (IU/mL)." The editorial office regrets the error. Full Article
en Clinical and imaging features of children with autoimmune encephalitis and MOG antibodies By nn.neurology.org Published On :: 2020-05-01T12:45:10-07:00 Objective To describe the presentations, radiologic features, and outcomes of children with autoimmune encephalitis associated with myelin oligodendrocyte glycoprotein antibodies (MOG abs). Methods Identification of children fulfilling the diagnostic criteria for possible autoimmune encephalitis (AE) and testing positive for serum MOG abs. Chart review and comprehensive analysis of serum MOG abs using live cell assays and rat brain immunohistochemistry. Results Ten children (4 girls, 6 boys) with AE and serum MOG abs were identified. The median age at onset was 8.0 years (range: 4–16 years). Children presented with a combination of encephalopathy (10/10), headache (7/10), focal neurologic signs (7/10), or seizures (6/10). CSF pleocytosis was common (9/10, median 80 white cell count/μL, range: 21–256). Imaging showed cortical and deep gray matter involvement in all in addition to juxtacortical signal alterations in 6/10 children. No involvement of other white matter structures or contrast enhancement was noted. MOG abs were detected in all children (median titer 1:640; range: 1:320–1:10,540). Nine children had a favorable outcome at discharge (modified Rankin scale of < 2). Five of 10 children had up to 3 additional demyelinating relapses associated with persisting MOG abs. One child had NMDA receptor (NMDAR) abs at initial presentation. A second child had a third demyelinating episode with MOG abs with overlapping NMDAR encephalitis. Discussion AE associated with serum MOG abs represents a distinct form of autoantibody-mediated encephalitis in children. We therefore recommend including MOG abs testing in the workup of children with suspected AE. Full Article
en Clinical approach to the diagnosis of autoimmune encephalitis in the pediatric patient By nn.neurology.org Published On :: 2020-04-15T14:12:14-07:00 Full Article
en Single-cycle rituximab-induced immunologic changes in children: Enhanced in neuroimmunologic disease? By nn.neurology.org Published On :: 2020-05-06T12:45:12-07:00 Objective To investigate the immunologic impact of a single cycle of rituximab (RTX) in children and adolescents with immune-mediated disorders, we evaluated B cells and immunoglobulin levels of 20 patients with neuroimmunologic, nephrologic, dermatologic, and rheumatologic disorders treated under recommended guidelines. Methods Retrospective study of immunologic changes in children (aged ≤18 years) diagnosed with immune-mediated disorders in which RTX was prescribed between June 2014 and February 2019. Patients were excluded if they had prior diagnosis of malignant disease or primary immunodeficiency. Patients were clinically and immunologically followed up every 3 months. Only patients having received a single cycle of RTX and with a follow-up greater than 12 months were included in the analysis of persistent dysgammaglobulinemia. Results Twenty children were included. Median age at RTX treatment was 12.8 years (interquartile range [IQR] 6.6–15.5 years). Median follow-up was 12.6 months (IQR 10.2–24 months). Of the 14 patients eligible for persistent dysgammaglobulinemia analysis (3 had received RTX retreatment, 2 had <12 months post-RTX follow-up, and in 1 data for this time point was missing), 2/14 (14%) remained with complete B-cell depletion, and 5/14 (36%) had dysgammaglobulinemia. Patients with dysgammaglobulinemia were younger (7.8 vs 15.6 years, p = 0.072), had more underlying neuroimmunologic diseases (5/5 vs 0/9, p < 0.001), and had received more frequently concentrated doses of RTX (3/5 vs 1/9, p = 0.05) than patients without dysgammaglobulinemia. Kinetics of immunoglobulins in the 20 patients revealed a decrease as early as 3 months after RTX in patients with neuroimmunologic disorders. Conclusion In our cohort, single-cycle RTX-induced dysgammaglobulinemia was enhanced in patients with neuroimmunologic diseases. Further studies are needed to confirm this observation. Full Article
en Monoclonal antibody treatment during pregnancy and/or lactation in women with MS or neuromyelitis optica spectrum disorder By nn.neurology.org Published On :: 2020-04-23T12:45:10-07:00 Objective To assess possible adverse effects on breastfed infants of mothers receiving monoclonal antibodies (MAbs) during pregnancy and/or lactation. Methods We identified 23 patients from the German Multiple Sclerosis and Pregnancy Registry (DMSKW) who received MAbs (17 natalizumab and 6 anti-CD20) during lactation. Thirteen were already exposed to natalizumab during the third trimester of pregnancy, and 1 received ocrelizumab during pregnancy. Data were obtained from standardized, telephone-administered questionnaires completed by the mother during pregnancy and at 1, 3, 6, and 12 months postpartum. Natalizumab concentration in mother’s milk was analyzed in 3 patients and natalizumab serum concentration in 2 of these patients and their breastfed infants. Results We did not observe a negative impact on infant health and development attributable to breast milk exposure after a median follow-up of 1 year. Infants exposed to natalizumab during the third trimester had a lower birth weight and more hospitalizations in the first year of life. The concentration of natalizumab in breast milk and serum of infants was low; B cells normal in infants breastfed under anti-CD20. Conclusion More data on the effect of Mab exposure during pregnancy are needed. Otherwise, our data suggest that treatment with natalizumab, ocrelizumab, or rituximab during lactation might be safe for breastfed infants. Full Article
en Clinical and MRI phenotypes of sarcoidosis-associated myelopathy By nn.neurology.org Published On :: 2020-04-08T12:45:09-07:00 Objective To determine the characteristic clinical and spinal MRI phenotypes of sarcoidosis-associated myelopathy (SAM), we analyzed a large cohort of patients with this disorder. Methods Patients diagnosed with SAM at a single center between 2000 and 2018 who met the established criteria for definite and probable neurosarcoidosis were included in a retrospective analysis to identify clinical profiles, CSF characteristics, and MRI lesion morphology. Results Of 62 included patients, 33 (53%) were male, and 30 (48%) were African American. SAM was the first clinical presentation of sarcoidosis in 49 patients (79%). Temporal profile of symptom evolution was chronic in 81%, with sensory symptoms most frequently reported (87%). CSF studies showed pleocytosis in 79% and CSF-restricted oligoclonal bands in 23% of samples tested. Four discrete patterns of lesion morphology were identified on spine MRI: longitudinally extensive myelitis (n = 28, 45%), short tumefactive myelitis (n = 14, 23%), spinal meningitis/meningoradiculitis (n = 14, 23%), and anterior myelitis associated with areas of disc degeneration (n = 6, 10%). Postgadolinium enhancement was seen in all but 1 patient during the acute phase. The most frequent enhancement pattern was dorsal subpial enhancement (n = 40), followed by meningeal/radicular enhancement (n = 23) and ventral subpial enhancement (n = 12). In 26 cases (42%), enhancement occurred at locations with coexisting structural changes (e.g., spondylosis). Conclusions Recognition of the clinical features (chronically evolving myelopathy) and distinct MRI phenotypes (with enhancement in a subpial and/or meningeal pattern) seen in SAM can aid diagnosis of this disorder. Enhancement patterns suggest that SAM may have a predilection for areas of the spinal cord susceptible to mechanical stress. Full Article
en Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy after alemtuzumab therapy in kidney transplant recipients By nn.neurology.org Published On :: 2020-04-16T12:45:11-07:00 Alemtuzumab is approved for the treatment of relapsing-remitting MS and is used off-label for patients with chronic lymphocytic leukemia and as induction and antirejection therapy in kidney transplant recipients.1 Guillain-Barré syndrome (GBS) or chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) complicating alemtuzumab treatment was reported in 9 patients with hematologic malignancy or MS.1–3 The risk of GBS or CIDP in solid organ transplant recipients treated with alemtuzumab is unknown. Full Article
en Ocrelizumab initiation in patients with MS: A multicenter observational study By nn.neurology.org Published On :: 2020-04-09T14:01:03-07:00 Objective To provide first real-world experience on patients with MS treated with the B cell–depleting antibody ocrelizumab. Methods We retrospectively collected data of patients who had received at least 1 treatment cycle (2 infusions) of ocrelizumab at 3 large neurology centers. Patients' characteristics including premedication, clinical disease course, and documented side effects were analyzed. Results We could identify 210 patients (125 women, mean age ± SD, 42.1 ± 11.4 years) who had received ocrelizumab with a mean disease duration of 7.3 years and a median Expanded Disability Status Scale score of 3.75 (interquartile range 2.5–5.5; range 0–8). Twenty-six percent of these patients had a primary progressive MS (PPMS), whereas 74% had a relapsing-remitting (RRMS) or active secondary progressive (aSPMS) disease course. Twenty-four percent of all patients were treatment naive, whereas 76% had received immune therapies before. After ocrelizumab initiation (median follow-up was 200 days, range 30–1,674 days), 13% of patients with RRMS/aSPMS experienced a relapse (accounting for an annualized relapse rate of 0.17, 95% CI 0.10–0.24), and 5% of all patients with MS experienced a 12-week confirmed disability progression. Treatment was generally well tolerated, albeit only short-term side effects were recorded, including direct infusion-related reactions and mild infections. Conclusions We provide class IV evidence that treatment with ocrelizumab can stabilize naive and pretreated patients, indicating that ocrelizumab is an option following potent MS drugs such as natalizumab and fingolimod. Further studies are warranted to confirm these findings and to reveal safety concerns in the longer-term follow-up. Classification of evidence This study provides Class IV evidence that for patients with MS, ocrelizumab can stabilize both treatment-naive and previously treated patients. Full Article
en Monitoring of radiologic disease activity by serum neurofilaments in MS By nn.neurology.org Published On :: 2020-04-09T14:01:03-07:00 Objective To determine whether serum neurofilament light chain (sNfL) levels are associated with recent MRI activity in patients with relapsing-remitting MS (RRMS). Methods This observational study included 163 patients (405 samples) with early RRMS from the Study of Early interferon-beta1a (IFN-β1a) Treatment (SET) cohort and 179 patients (664 samples) with more advanced RRMS from the Genome-Wide Association Study of Multiple Sclerosis (GeneMSA) cohort. Based on annual brain MRI, we assessed the ability of sNfL cutoffs to reflect the presence of combined unique active lesions, defined as new/enlarging lesion compared with MRI in the preceding year or contrast-enhancing lesion. The probability of active MRI lesions among patients with different sNfL levels was estimated with generalized estimating equations models. Results From the sNfL samples ≥90th percentile, 81.6% of the SET (OR = 3.4, 95% CI = 1.8-6.4) and 48.9% of the GeneMSA cohort samples (OR = 2.6, 95% CI = 1.7-3.9) was associated with radiological disease activity on MRI. The sNfL level between the 10th and 30th percentile was reflective of negligible MRI activity: 1.4% (SET) and 6.5% (GeneMSA) of patients developed ≥3 active lesions, 5.8% (SET) and 6.5% (GeneMSA) developed ≥2 active lesions, and 34.8% (SET) and 11.8% (GeneMSA) showed ≥1 active lesion on brain MRI. The sNfL level <10th percentile was associated with even lower MRI activity. Similar results were found in a subgroup of clinically stable patients. Conclusions Low sNfL levels (≤30th percentile) help identify patients with MS with very low probability of recent radiologic disease activity during the preceding year. This result suggests that in future, sNfL assessment may substitute the need for annual brain MRI monitoring in considerable number (23.1%–36.4%) of visits in clinically stable patients. Full Article
en Geospatial assessment methods for geotechnical asset management of legacy railway embankments By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 Most British railway embankments were constructed between 120 and 180 years ago without the benefit of modern design and construction methods. This can result in undesirable load-deformation characteristics and consequent disruption to present-day railway operations, for which there is unprecedented demand. Annual rail passenger kilometres have approximately doubled in the last 20 years and freight has increased by 60% over the same period. Whereas elements such as rails or bridges can be refurbished or replaced to meet increasing demand, the same is not usually feasible for embankments. Development of techniques to assess embankment performance risks posed by operational capacity enhancements is therefore of increasing significance to railway geotechnical asset management. The two case studies presented in this paper demonstrate how geospatial analysis and data management techniques may be applied to this challenge at both strategic (regional or national) and tactical (site-specific) scales for embankments incorporating plastic clay fill. The case studies also demonstrate, in a world of ever more abundant data, the growing need for engineering geologists and geotechnical engineers to augment their traditional knowledge with comprehensive data management and geospatial analysis skills, these being essential for modern infrastructure asset management. Thematic collection: This article is part of the ‘Ground-related risk to transportation infrastructure’ collection available at: https://www.lyellcollection.org/cc/Ground-related-risk-to-transportation-infrastructure Full Article
en Establishing and quantifying the causal linkage between drainage and earthworks performance for Highways England By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 Transportation infrastructure owners manage an array of different asset types such as bridges, road pavements, earthworks and drainage. Currently, most organization management procedures are siloed by asset type; however, there are important interactions between these asset groups that need to be managed in a cross-asset way. Although these interactions are known, there is little or no quantification of these interactions. For the first time, this paper quantifies that 74% of Highways England's earthwork failures are a result of drainage-related problems, either the lack of drainage infrastructure or the poor performance of it. The analysis undertaken is an important first step not only in moving towards more connected asset management planning for earthworks and drainage, but to also provide guidance for other owners of earthwork infrastructure assets to improve their strategic asset management procedures. Thematic collection: This article is part of the Ground-related risk to transportation infrastructure collection available at https://www.lyellcollection.org/cc/Ground-related-risk-to-transportation-infrastructure Full Article
en The identification and mitigation of geohazards using shallow airborne engineering geophysics and land-based geophysics for brown- and greenfield road investigations By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 South Africa is a mineral-rich country with a diverse geology and a long history of mining. The rich history of mining activities includes the extraction of coal from the Ecca Group Sediments of the Karoo Supergroup (250 Ma), gold and uranium from the Witwatersrand Supergroup (2900 Ma), as well as platinum, uranium, tin and lead from the layered Bushveld Igneous Complex (BIC) (2150 Ma). The extraction of gold, copper, tin, lead and rare earth minerals also took place in the Archean rocks of Swazium age (3500–3000 Ma). The historical mining records have either not been accurately recorded or have been lost over time. This has resulted in significant geohazard risk during infrastructure development, especially in and around historical mining towns, such as Johannesburg and Ermelo. These geohazard risks require careful appraisal and quantification prior to any infrastructure design or construction. This case study aims to set out the development aspects of the Multi-Faceted Geophysical Modelling Systems approach, which was used by the South African National Roads Agency SOC Ltd (SANRAL) during an investigation of undermined ground for the historical coal-mining town of Ermelo in South Africa. The N11/N2 ring road was planned to go around Ermelo to ensure mobility between major routes, whilst still maintaining town access. The systems approach used a combination of airborne geophysics (Versatile Time Domain Electromagnetic System (VTEMTM) and magnetics), generally used in mining exploration, land-based and borehole geophysics, borehole water testing, and ground-truthing. The approach was continuous and iterative, building on the data at hand and reducing unnecessary investigations while eliminating the possibility of anomalies being missed, as in the case of conventional discrete drilling. The investigation ensured that 100% of the route was comprehensively investigated with a high confidence in the geological and geophysical data, and concomitant mitigation of infrastructure risk. The Multi-Faceted Geophysical Modelling Systems approach was successfully used to identify a previously unknown 1 x 1 m mining stope cavity at 90 m depth and a 3 x 5 m access tunnel at 24 m depth in a timely and cost-effective manner. Seven reverse-circulation percussion boreholes confirmed the structural integrity of these underground cavities, as well as the structural geology along the centreline. Based on the great success achieved in identifying shallow anomalies, this Multi-Faceted Geophysical Modelling Systems approach is now being considered for field trails on the dolomitic formations and the Wild Coast greenfields road project where there are large historical slumps and many fault lines. Thematic collection: This article is part of the Ground-related risk to transportation infrastructure collection available at https://www.lyellcollection.org/cc/Ground-related-risk-to-transportation-infrastructure Full Article
en Strategic geotechnical asset management By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 Strategic geotechnical asset management considers the whole of an organization's earthworks portfolio and is concerned with setting an overall earthworks asset management policy with long-term objectives related to asset performance, safety and condition, and identifying how those objectives can best be met, now and into the future. A risk-based approach is adopted that requires an understanding of the likelihood that any of the earthworks may fail, combined with a knowledge of the consequences should they fail. Procedures are required to identify those earthworks that are most vulnerable to failure under the influence of triggering events, such as extreme weather. The risks are managed through a mix of interventions to reduce the likelihood of failure and mitigations to reduce the impact of failure. Many of the challenges of implementing a strategic earthworks policy have, or are, being met by the main UK transportation infrastructure organizations. Thematic collection: This article is part of the Ground-related risk to transportation infrastructure collection available at https://www.lyellcollection.org/cc/Ground-related-risk-to-transportation-infrastructure Full Article
en Effect of depositional water content on the collapsibility of a reconstituted loess By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 Loess, a wind-blown silty soil, can be deposited under a variety of moisture conditions, including dry deposition, wet deposition and gravitational settling of aggregations formed in moist air by capillary forces at grain contacts. This experimental study uses single and double oedometer tests to assess the effect of depositional water content on the collapse potential of reconstituted samples of the Langley Silt Member, known as Brickearth, a natural loessic soil. A freefall sample preparation technique was used to mimic loess formation and environmental scanning electron microscopy was used to relate the observed behaviour to sample fabric. The results show that loess deposited at higher water contents has a greater collapse potential, which is shown to be related to its looser, more granular fabric. Full Article
en A case study for identification of organic-silt bottom sediments in an artificial lake formed in gravel alluvium in the geotourism locality of Slnecne Jazera in Senec (Bratislava, Slovakia) By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 This case study aims to identify the cubic capacity and geometry of the geological body of silt–organic sediments in the environment of a former gravel pit situated in a drainless depression of the alluvium of the Čierna voda River. It is located in the well-known geotourism locality of Slnečné Jazera in Senec, in the SW of Slovakia. To identify the body, electrical resistivity tomography was combined with the use of sonar. The research shows that this approach is appropriate for a number of activities that are subjects of engineering-geological investigations. The cubic capacity and geometry of specific aqueous engineering-geological environments must be determined in connection with the need for the management, control, quantification and extraction of selected sedimentary bodies. In addition, the management of sustainable development of reservoirs, sedimentation basins, industrial ponds, settling pits and natural pools for recreation (the subject of the case study) is important to control the limit amounts of sediments in such environments. The results of this study may be applied in analogous engineering-geological conditions. The drainless depression Slnečné Jazera contained a body of silt–organic sediments amounting to 23 000 m3 (41 Olympic-size pools of 25 m x 12.5 m x 1.8 m). The maximum thickness of the bottom sediments was about 6.3 m on the alluvium with an articulated morphology owing to the submerged digging of gravel. The proposed approach improved the control of extraction of the sedimentary body and optimized the engineering-geological conditions in this geotourism locality. Full Article
en Prediction of tunnelling impact on flow rates of adjacent extraction water wells By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 The decline or drying up of groundwater sources near a tunnel route is damaging to groundwater users. Therefore, forecasting the impact of a tunnel on nearby groundwater sources is a challenging task in tunnel design. In this study, numerical and analytical approaches were applied to the Qomroud water conveyance tunnel (located in Lorestan province, Iran) to assess the impact of tunnelling on the nearby extraction water wells. Using simulation of groundwater-level fluctuation owing to tunnelling, the drawdown at the well locations was determined. From the drawdowns and using Dupuit's equation, the depletion of well flow rates after tunnelling was estimated. To evaluate the results, observed well flow rates before and after tunnelling were compared with the predicted flow rates. The observed and estimated water well flows (before and after tunnelling) showed a regression factor of 0.64, pointing to satisfactory results Full Article
en The origin and pedogenesis of the Clay-with-flints Formation By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 The Clay-with-flints Formation outcrops on the high chalk plateaux and interfluves of the chalk downs in southern England. Both current and historical definitions of the Clay-with-flints are detailed and important distinctions are identified with other deposits that appear identical but are formed in different ways. Historically pedological or geomorphological studies have been carried out on the deposit. Engineering studies are only carried out where the deposit is crossed by infrastructure. The physical and chemical processes acting on the deposit and the resulting effects on the physical properties are discussed. Full Article
en Decision tree as a tool for the management of coastal aquifers of limited saturated thickness By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 In this paper, a decision tree is presented, constructed on the basis of hydrogeological characteristics (water table depth, freshwater thickness, surface area required and distance between wells), to choose the optimal groundwater extraction method in the case of a coastal unconfined aquifer. A comparison is made of the groundwater extraction methods in a freshwater aquifer of limited thickness occurring in coastal dunes in the eastern region of the Province of Buenos Aires (Argentina). The negative effects brought about by the wrong use of the groundwater extraction methods are analysed, because, as a result of excessive extraction, such methods lead to the dramatic decrease of the freshwater reserves. The decision tree is a useful tool to assist decision-makers as it suggests the most suitable groundwater extraction method options (vertical wells or wellpoints), as well as identifying areas that are unsuitable for sustainable groundwater extraction. Full Article
en Fluorescent Hybridization of Mycobacterium leprae in Skin Samples Collected in Burkina Faso [Mycobacteriology and Aerobic Actinomycetes] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Leprosy is caused by Mycobacterium leprae, and it remains underdiagnosed in Burkina Faso. We investigated the use of fluorescent in situ hybridization (FISH) for detecting M. leprae in 27 skin samples (skin biopsy samples, slit skin samples, and skin lesion swabs) collected from 21 patients from Burkina Faso and three from Côte d’Ivoire who were suspected of having cutaneous leprosy. In all seven Ziehl-Neelsen-positive skin samples (four skin biopsy samples and three skin swabs collected from the same patient), FISH specifically identified M. leprae, including one FISH-positive skin biopsy sample that remained negative after testing with PCR targeting the rpoB gene and with the GenoType LepraeDR assay. Twenty other skin samples and three negative controls all remained negative for Ziehl-Neelsen staining, FISH, and rpoB PCR. These data indicate the usefulness of a microscopic examination of skin samples after FISH for first-line diagnosis of cutaneous leprosy. Accordingly, FISH represents a potentially useful point-of-care test for the diagnosis of cutaneous leprosy. Full Article
en Nanopore Sequencing Reveals Novel Targets for Detection and Surveillance of Human and Avian Influenza A Viruses [Virology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Accurate detection of influenza A virus (IAV) is crucial for patient management, infection control, and epidemiological surveillance. The World Health Organization and the Centers for Disease Control and Prevention have recommended using the M gene as the diagnostic gene target for reverse-transcription-PCR (RT-PCR). However, M gene RT-PCR has reduced sensitivity for recent IAV due to novel gene mutations. Here, we sought to identify novel diagnostic targets for the molecular detection of IAV using long-read third-generation sequencing. Direct nanopore sequencing from 18 nasopharyngeal specimens and one saliva specimen showed that the 5' and 3' ends of the PB2 gene and the entire NS gene were highly abundant. Primers selected for PB2 and NS genes were well matched with seasonal or avian IAV gene sequences. Our novel PB2 and NS gene real-time RT-PCR assays showed limits of detection similar to or lower than that of M gene RT-PCR and achieved 100% sensitivity and specificity in the detection of A(H1N1), A(H3N2), and A(H7N9) in nasopharyngeal and saliva specimens. For 10 patients with IAV detected by M gene RT-PCR conversion in sequentially collected specimens, NS and/or PB2 gene RT-PCR was positive in 2 (20%) of the initial specimens that were missed by M gene RT-PCR. In conclusion, we have shown that PB2 or NS gene RT-PCRs are suitable alternatives to the recommended M gene RT-PCR for diagnosis of IAV. Long-read nanopore sequencing facilitates the identification of novel diagnostic targets. Full Article
en Multicenter Evaluation of a PCR-Based Digital Microfluidics and Electrochemical Detection System for the Rapid Identification of 15 Fungal Pathogens Directly from Positive Blood Cultures [Mycology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Routine identification of fungal pathogens from positive blood cultures by culture-based methods can be time-consuming, delaying treatment with appropriate antifungal agents. The GenMark Dx ePlex investigational use only blood culture identification fungal pathogen panel (BCID-FP) rapidly detects 15 fungal targets simultaneously in blood culture samples positive for fungi by Gram staining. We aimed to determine the performance of the BCID-FP in a multicenter clinical study. Blood culture samples collected at 10 United States sites and tested with BCID-FP at 4 sites were compared to the standard-of-care microbiological and biochemical techniques, fluorescence in situ hybridization using peptide nucleic acid probes (PNA-FISH) and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Discrepant results were analyzed by bi-directional PCR/sequencing of residual blood culture samples. A total of 866 clinical samples, 120 retrospectively and 21 prospectively collected, along with 725 contrived samples were evaluated. Sensitivity and specificity of detection of Candida species (C. albicans, C. auris, C. dubliniensis, C. famata, C. glabrata, C. guilliermondii, C. kefyr, C. krusei, C. lusitaniae, C. parapsilosis, and C. tropicalis) ranged from 97.1 to 100% and 99.8 to 100%, respectively. For the other organism targets, sensitivity and specificity were as follows: 100% each for Cryptococcus neoformans and C. gattii, 98.6% and 100% for Fusarium spp., and 96.2% and 99.9% for Rhodotorula spp., respectively. In 4 of the 141 clinical samples, the BCID-FP panel correctly identified an additional Candida species, undetected by standard-of-care methods. The BCID-FP panel offers a faster turnaround time for identification of fungal pathogens in positive blood cultures that may allow for earlier antifungal interventions and includes C. auris, a highly multidrug-resistant fungus. Full Article
en Differentiation of Community-Associated and Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates and Identification of spa Types by Use of PCR and High-Resolution Melt Curve Analysis [Clinical Veterinary Microbiology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Infections due to methicillin-resistant Staphylococcus aureus (MRSA) are present worldwide and represent a major public health concern. The capability of PCR followed by high-resolution melt (HRM) curve analysis for the detection of community-associated and livestock-associated MRSA strains and the identification of staphylococcal protein A (spa) locus was evaluated in 74 MRSA samples which were isolated from the environment, humans, and pigs on a single piggery. PCR-HRM curve analysis identified four spa types among MRSA samples and differentiated MRSA strains accordingly. A nonsubjective differentiation model was developed according to genetic confidence percentage values produced by tested samples, which did not require visual interpretation of HRM curve results. The test was carried out at different settings, and result data were reanalyzed and confirmed with DNA sequencing. PCR-HRM curve analysis proved to be a robust and reliable test for spa typing and can be used as a tool in epidemiological studies. Full Article
en High-Content Screening, a Reliable System for Coxiella burnetii Isolation from Clinical Samples [Bacteriology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Q fever, caused by Coxiella burnetii, is a worldwide zoonotic disease that may cause severe forms in humans and requires a specific and prolonged antibiotic treatment. Although current serological and molecular detection tools allow a reliable diagnosis of the disease, culture of C. burnetii strains is mandatory to assess their susceptibility to antibiotics and sequence their genome in order to optimize patient management and epidemiological studies. However, cultivating this fastidious microorganism is difficult and restricted to reference centers, as it requires biosafety level 3 laboratories and relies on cell culture performed by experienced technicians. In addition, the culture yield is low, which results in a small number of isolates being available. In this work, we developed a novel high-content screening (HCS) isolation strategy based on optimized high-throughput cell culture and automated microscopic detection of infected cells with specifically designed algorithms targeting cytopathic effects. This method was more efficient than the shell vial assay, at the level of time dependency, when applied to both frozen specimens (7 isolates recovered by HCS only, sensitivity 91% versus 78% for shell vial) and fresh samples (1 additional isolate using HCS, sensitivity 7% versus 5% for shell vial), for which most strains were recovered more rapidly with the new technique. In addition, detecting positive cultures by an automated microscope reduced the need for expertise and saved 24% of technician working time. Application of HCS to antibiotic susceptibility testing of 12 strains demonstrated that it was as efficient as the standard procedure that combines shell vial culture and quantitative PCR. Full Article
en Genomic Investigation Reveals Contaminated Detergent as the Source of an Extended-Spectrum-{beta}-Lactamase-Producing Klebsiella michiganensis Outbreak in a Neonatal Unit [Bacteriology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Klebsiella species are problematic pathogens in neonatal units and may cause outbreaks, for which the sources of transmission may be challenging to elucidate. We describe the use of whole-genome sequencing (WGS) to investigate environmental sources of transmission during an outbreak of extended-spectrum-β-lactamase (ESBL)-producing Klebsiella michiganensis colonizing neonates. Ceftriaxone-resistant Klebsiella spp. isolated from neonates (or their mothers) and the hospital environment were included. Short-read sequencing (Illumina) and long-read sequencing (MinION; Oxford Nanopore Technologies) were used to confirm species taxonomy, to identify antimicrobial resistance genes, and to determine phylogenetic relationships using single-nucleotide polymorphism profiling. A total of 21 organisms (10 patient-derived isolates and 11 environmental isolates) were sequenced. Standard laboratory methods identified the outbreak strain as an ESBL-producing Klebsiella oxytoca, but taxonomic assignment from WGS data suggested closer identity to Klebsiella michiganensis. Strains isolated from multiple detergent-dispensing bottles were either identical or closely related by single-nucleotide polymorphism comparison. Detergent bottles contaminated by K. michiganensis had been used for washing milk expression equipment. No new cases were identified once the detergent bottles were removed. Environmental reservoirs may be an important source in outbreaks of multidrug-resistant organisms. WGS, in conjunction with traditional epidemiological investigation, can be instrumental in revealing routes of transmission and guiding infection control responses. Full Article
en Pooling Pharyngeal, Anorectal, and Urogenital Samples for Screening Asymptomatic Men Who Have Sex with Men for Chlamydia trachomatis and Neisseria gonorrhoeae [Bacteriology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Screening for Chlamydia trachomatis and Neisseria gonorrhoeae at the pharyngeal, urogenital, and anorectal sites is recommended for men who have sex with men (MSM). Combining the three individual-site samples into a single pooled sample could result in significant cost savings, provided there is no significant sensitivity reduction. The aim of this study was to examine the sensitivity of pooled samples for detecting chlamydia and gonorrhea in asymptomatic MSM using a nucleic acid amplification test. Asymptomatic MSM who tested positive for chlamydia or gonorrhoea were invited to participate. Paired samples were obtained from participants prior to administration of treatment. To form the pooled sample, the anorectal swab was agitated in the urine specimen transport tube and then discarded. The pharyngeal swab and 2 ml of urine sample were then added to the tube. The difference in sensitivity between testing of pooled samples and individual-site testing was calculated against an expanded gold standard, where an individual is considered positive if either pooled-sample or individual-site testing returns a positive result. All samples were tested using the Aptima Combo 2 assay. A total of 162 MSM were enrolled in the study. Sensitivities of pooled-sample testing were 86% (94/109; 95% confidence interval [CI], 79 to 92%]) for chlamydia and 91% (73/80; 95% CI, 83 to 96%) for gonorrhea. The sensitivity reduction was significant for chlamydia (P = 0.02) but not for gonorrhea (P = 0.34). Pooling caused 22 infections (15 chlamydia and 7 gonorrhoea) to be missed, and the majority were single-site infections (19/22). Pooling urogenital and extragenital samples from asymptomatic MSM reduced the sensitivity of detection by approximately 10% for chlamydia but not for gonorrhea. Full Article
en Recombinase Polymerase Amplification and Lateral Flow Assay for Ultrasensitive Detection of Low-Density Plasmodium falciparum Infection from Controlled Human Malaria Infection Studies and Naturally Acquired Infections [Parasitology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Microscopy and rapid diagnostic tests (RDTs) are the main diagnostic tools for malaria but fail to detect low-density parasitemias that are important for maintaining malaria transmission. To complement existing diagnostic methods, an isothermal reverse transcription-recombinase polymerase amplification and lateral flow assay (RT-RPA) was developed. We compared the performance with that of ultrasensitive reverse transcription-quantitative PCR (uRT-qPCR) using nucleic acid extracts from blood samples (n = 114) obtained after standardized controlled human malaria infection (CHMI) with Plasmodium falciparum sporozoites. As a preliminary investigation, we also sampled asymptomatic individuals (n = 28) in an area of malaria endemicity (Lambaréné, Gabon) to validate RT-RPA and assess its performance with unprocessed blood samples (dbRT-RPA). In 114 samples analyzed from CHMI trials, the positive percent agreement to uRT-qPCR was 90% (95% confidence interval [CI], 80 to 96). The negative percent agreement was 100% (95% CI, 92 to 100). The lower limit of detection was 64 parasites/ml. In Gabon, RT-RPA was 100% accurate with asymptomatic volunteers (n = 28), while simplified dbRT-RPA showed 89% accuracy. In a subgroup analysis, RT-RPA detected 9/10 RT-qPCR-positive samples, while loop-mediated isothermal amplification (LAMP) detected 2/10. RT-RPA is a reliable diagnostic test for asymptomatic low-density infections. It is particularly useful in settings where uRT-qPCR is difficult to implement. Full Article
en A Fully Automated Multiplex Assay for Diagnosis of Lyme Disease with High Specificity and Improved Early Sensitivity [Immunoassays] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Lyme borreliosis is a tick-borne disease caused by the Borrelia burgdorferi sensu lato complex. Bio-Rad Laboratories has developed a fully automated multiplex bead-based assay for the detection of IgM and IgG antibodies to B. burgdorferi. The BioPlex 2200 Lyme Total assay exhibits an improved rate of seropositivity in patients with early Lyme infection. Asymptomatic subjects from endemic and nonendemic origins demonstrated a seroreactivity rate of approximately 4% that was similar to other commercial assays evaluated in this study. Coupled to this result was the observation that the Lyme Total assay retained a high first-tier specificity of 96% while demonstrating a relatively high sensitivity of 91% among a well-characterized CDC Premarketing Lyme serum panel. The Lyme Total assay also performs well under a modified two-tier algorithm (sensitivity, 84.4 to 88.9%; specificity, 98.4 to 99.5%). Furthermore, the new assay is able to readily detect early Lyme infection in patient samples from outside North America. Full Article
en Development of a Sensitive and Rapid Recombinase Polymerase Amplification Assay for Detection of Anaplasma phagocytophilum [Chlamydiology and Rickettsiology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Human granulocytic anaplasmosis (HGA) is a tick-borne disease caused by the obligate intracellular Gram-negative bacterium Anaplasma phagocytophilum. The disease often presents with nonspecific symptoms with negative serology during the acute phase. Direct pathogen detection is the best approach for early confirmatory diagnosis. Over the years, PCR-based molecular detection methods have been developed, but optimal sensitivity is not achieved by conventional PCR while real-time PCR requires expensive and sophisticated instruments. To improve the sensitivity and also develop an assay that can be used in resource-limited areas, an isothermal DNA amplification assay based on recombinase polymerase amplification (RPA) was developed. To do this, we identified a 171-bp DNA sequence within multiple paralogous copies of msp2 within the genome of A. phagocytophilum. Our novel RPA assay targeting this sequence has an analytical limit of detection of one genome equivalent copy of A. phagocytophilum and can reliably detect 125 bacteria/ml in human blood. A high level of specificity was demonstrated by the absence of nonspecific amplification using genomic DNA from human or DNA from other closely-related pathogenic bacteria, such as Anaplasma platys, Ehrlichia chaffeensis, Orientia tsutsugamushi, and Rickettsia rickettsii, etc. When applied to patient DNA extracted from whole blood, this new RPA assay was able to detect 100% of previously diagnosed A. phagocytophilum cases. The sensitivity and rapidness of this assay represents a major improvement for early diagnosis of A. phagocytophilum in human patients and suggest a role for better surveillance in its reservoirs or vectors, especially in remote regions where resources are limited. Full Article
en Multicenter Evaluation of the BD Phoenix CPO Detect Test for Detection and Classification of Carbapenemase-Producing Organisms in Clinical Isolates [Bacteriology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 Limited treatment options contribute to high morbidity/mortality rates with carbapenem-resistant, Gram-negative bacterial infections. New approaches for carbapenemase-producing organism (CPO) detection may help inform clinician decision-making on patient treatment and infection control. BD Phoenix CPO detect (CPO detect) detects and classifies carbapenemases in Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa during susceptibility testing. The clinical performance of CPO detect is reported here. Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa isolates were evaluated across three sites using CPO detect and a composite reference method (RM); the latter was comprised of the modified carbapenem inactivation method and a MIC screen for ertapenem, imipenem, and meropenem. Multiplex PCR testing was also utilized for Ambler class determination. Positive and negative percentages of agreement (PPA and NPA, respectively) between CPO detect and the RM were determined. The PPA and NPA for Enterobacterales were 98.5% (confidence intervals, 96.6%, 99.4%) and 97.2% (95.8%, 98.2%), respectively. The A. baumannii PPA and NPA, respectively, were 97.1% (90.2%, 99.2%) and 97.1% (89.9%, 99.2%). The P. aeruginosa PPA and NPA, respectively, were 95.9% (88.6%, 98.6%) and 92.3% (86.7%, 95.6%). The PPA values for carbapenemase class designations for all organisms combined and Enterobacterales alone, respectively, were 95.3% (90.2%, 97.8%) and 94.6% (88.8%, 97.5%) for class A, 94.0% (88.7%, 96.6%) and 96.4% (90.0%, 98.8%) for class B, and 95.0% (90.1%, 97.6%) and 99.0% (94.4%, 99.8%) for class D carbapenemases. NPA values for all organisms and Enterobacterales alone ranged from 98.5% to 100%. CPO detect provided accurate detection and classification of CPOs for the majority of isolates of Enterobacterales, Acinetobacter baumannii, and Pseudomonas aeruginosa tested. Full Article
en Evaluation of ID Fungi Plates Medium for Identification of Molds by MALDI Biotyper [Mycology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 MALDI-TOF mass spectrometry (MS) identification of pathogenic filamentous fungi is often impaired by difficulties in harvesting hyphae embedded in the medium and long extraction protocols. The ID Fungi Plate (IDFP) is a novel culture method developed to address such difficulties and improve the identification of filamentous fungi by MALDI-TOF MS. We cultured 64 strains and 11 clinical samples on IDFP, Sabouraud agar-chloramphenicol (SAB), and ChromID Candida agar (CAN2). We then compared the three media for growth, ease of harvest, amount of material picked, and MALDI-TOF identification scores after either rapid direct transfer (DT) or a long ethanol-acetonitrile (EA) extraction protocol. Antifungal susceptibility testing and microscopic morphology after subculture on SAB and IDFP were also compared for ten molds. Growth rates and morphological aspects were similar for the three media. With IDFP, harvesting of fungal material for the extraction procedure was rapid and easy in 92.4% of cases, whereas it was tedious on SAB or CAN2 in 65.2% and 80.3% of cases, respectively. The proportion of scores above 1.7 (defined as acceptable identification) were comparable for both extraction protocols using IDFP (P = 0.256). Moreover, rates of acceptable identification after DT performed on IDFP (93.9%) were significantly higher than those obtained after EA extraction with SAB (69.7%) or CAN2 (71.2%) (P = <0.001 and P = 0.001, respectively). Morphological aspects and antifungal susceptibility testing were similar between IDFP and SAB. IDFP is a culture plate that facilitates and improves the identification of filamentous fungi, allowing accurate routine identification of molds with MALDI-TOF-MS using a rapid-extraction protocol. Full Article
en Evaluation of Cycle Threshold, Toxin Concentration, and Clinical Characteristics of Clostridioides difficile Infection in Patients with Discordant Diagnostic Test Results [Bacteriology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 Clostridioides difficile infection (CDI) is one of the most common health care-associated infections that can cause significant morbidity and mortality. CDI diagnosis involves laboratory testing in conjunction with clinical assessment. The objective of this study was to assess the performance of various C. difficile tests and to compare clinical characteristics, Xpert C. difficile/Epi (PCR) cycle threshold (CT), and Singulex Clarity C. diff toxins A/B (Clarity) concentrations between groups with discordant test results. Unformed stool specimens from 200 hospitalized adults (100 PCR positive and 100 negative) were tested by cell cytotoxicity neutralization assay (CCNA), C. diff Quik Chek Complete (Quik Chek), Premier Toxins A and B, and Clarity. Clinical data, including CDI severity and CDI risk factors, were compared between discordant test results. Compared to CCNA, PCR had the highest sensitivity at 100% and Quik Chek had the highest specificity at 100%. Among clinical and laboratory data studied, prevalences of leukocytosis, prior antibiotic use, and hospitalizations were consistently higher across all subgroups in comparisons of toxin-positive to toxin-negative patients. Among PCR-positive samples, the median CT was lower in toxin-positive samples than in toxin-negative samples; however, CT ranges overlapped. Among Clarity-positive samples, the quantitative toxin concentration was significantly higher in toxin-positive samples than in toxin-negative samples as determined by CCNA and Quik Chek Toxin A and B. Laboratory tests for CDI vary in sensitivity and specificity. The quantitative toxin concentration may offer value in guiding CDI diagnosis and treatment. The presence of leukocytosis, prior antibiotic use, and previous hospitalizations may assist with CDI diagnosis, while other clinical parameters may not be consistently reliable. Full Article
en Development of a Novel and Rapid Antibody-Based Diagnostic for Chronic Staphylococcus aureus Infections Based on Biofilm Antigens [Immunoassays] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 Prosthetic joint infections are difficult to diagnose and treat due to biofilm formation by the causative pathogens. Pathogen identification relies on microbial culture that requires days to weeks, and in the case of chronic biofilm infections, lacks sensitivity. Diagnosis of infection is often delayed past the point of effective treatment such that only the removal of the implant is curative. Early diagnosis of an infection based on antibody detection might lead to less invasive, early interventions. Our study examined antibody-based assays against the Staphylococcus aureus biofilm-upregulated antigens SAOCOL0486 (a lipoprotein), glucosaminidase (a domain of SACOL1062), and SACOL0688 (the manganese transporter MntC) for detection of chronic S. aureus infection. We evaluated these antigens by enzyme-linked immunosorbent assay (ELISA) using sera from naive rabbits and rabbits with S. aureus-mediated osteomyelitis, and then we validated a proof of concept for the lateral flow assay (LFA). The SACOL0688 LFA demonstrated 100% specificity and 100% sensitivity. We demonstrated the clinical diagnostic utility of the SACOL0688 antigen using synovial fluid (SF) from humans with orthopedic implant infections. Elevated antibody levels to SACOL0688 in clinical SF specimens correlated with 91% sensitivity and 100% specificity for the diagnosis of S. aureus infection by ELISA. We found measuring antibodies levels to SACOL0688 in SF using ELISA or LFA provides a tool for the sensitive and specific diagnosis of S. aureus prosthetic joint infection. Development of the LFA diagnostic modality is a desirable, cost-effective option, potentially providing rapid readout in minutes for chronic biofilm infections. Full Article
en Pharmacy-Based Infectious Disease Management Programs Incorporating CLIA-Waived Point-of-Care Tests [Minireviews] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 There are roughly 48,000 deaths caused by influenza annually and an estimated 200,000 people who have undiagnosed human immunodeficiency virus (HIV). These are examples of acute and chronic illnesses that can be identified by employing a CLIA-waived test. Pharmacies across the country have been incorporating CLIA-waived point-of-care tests (POCT) into disease screening and management programs offered in the pharmacy. The rationale behind these programs is discussed. Additionally, a summary of clinical data for some of these programs in the infectious disease arena is provided. Finally, we discuss the future potential for CLIA-waived POCT-based programs in community pharmacies. Full Article
en Pathogen or Bystander: Clinical Significance of Detecting Human Herpesvirus 6 in Pediatric Cerebrospinal Fluid [Virology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 Human herpesvirus 6 (HHV-6) is an important cause of meningitis and meningoencephalitis. As testing for HHV-6 in cerebrospinal fluid (CSF) is more readily available using the FilmArray Meningitis/Encephalitis panel (FA-ME; BioFire Diagnostics, Salt Lake City, UT), we aimed to determine the clinical significance of detecting HHV-6 in order to identify true infections and to ensure appropriate antiviral initiation. Chart review on 25 patients positive for HHV-6 by FA-ME was performed to determine clinical presentation, comorbidity, treatment, and outcome. The presence of chromosomally integrated HHV-6 (ciHHV-6) DNA was also investigated. Of 1,005 children tested by FA-ME, HHV-6 was detected in 25 (2.5%). Five patients were diagnosed with either HHV-6 meningitis or meningoencephalitis based on HHV-6 detection in CSF, clinical presentation, and radiographic findings. Detection of HHV-6 by FA-ME led to discontinuation of acyclovir within 12.0 h in all 12 patients empirically treated with acyclovir. Six of the 12 patients were started on ganciclovir therapy within 6.8 h; 4 of these were treated specifically for HHV-6 infection, whereas therapy was discontinued in the remaining 2 patients. CSF parameters were not generally predictive of HHV-6 positivity. The presence of ciHHV-6 was confirmed in 3 of 18 patients who could be tested. Five of the 25 patients included in the study were diagnosed with HHV-6 meningitis/meningoencephalitis. FA-ME results led to discontinuation of empirical antiviral treatment in 12 patients and appropriate initiation of ganciclovir in 4 patients. In our institution, detection of HHV-6 using FA-ME led to faster establishment of disease etiology and optimization of antimicrobial therapy. Full Article
en Improved Molecular Diagnosis of COVID-19 by the Novel, Highly Sensitive and Specific COVID-19-RdRp/Hel Real-Time Reverse Transcription-PCR Assay Validated In Vitro and with Clinical Specimens [Virology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 On 31 December 2019, the World Health Organization was informed of a cluster of cases of pneumonia of unknown etiology in Wuhan, China. Subsequent investigations identified a novel coronavirus, now named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), from the affected patients. Highly sensitive and specific laboratory diagnostics are important for controlling the rapidly evolving SARS-CoV-2-associated coronavirus disease 2019 (COVID-19) epidemic. In this study, we developed and compared the performance of three novel real-time reverse transcription-PCR (RT-PCR) assays targeting the RNA-dependent RNA polymerase (RdRp)/helicase (Hel), spike (S), and nucleocapsid (N) genes of SARS-CoV-2 with that of the reported RdRp-P2 assay, which is used in >30 European laboratories. Among the three novel assays, the COVID-19-RdRp/Hel assay had the lowest limit of detection in vitro (1.8 50% tissue culture infective doses [TCID50]/ml with genomic RNA and 11.2 RNA copies/reaction with in vitro RNA transcripts). Among 273 specimens from 15 patients with laboratory-confirmed COVID-19 in Hong Kong, 77 (28.2%) were positive by both the COVID-19-RdRp/Hel and RdRp-P2 assays. The COVID-19-RdRp/Hel assay was positive for an additional 42 RdRp-P2-negative specimens (119/273 [43.6%] versus 77/273 [28.2%]; P < 0.001), including 29/120 (24.2%) respiratory tract specimens and 13/153 (8.5%) non-respiratory tract specimens. The mean viral load of these specimens was 3.21 x 104 RNA copies/ml (range, 2.21 x 102 to 4.71 x 105 RNA copies/ml). The COVID-19-RdRp/Hel assay did not cross-react with other human-pathogenic coronaviruses and respiratory pathogens in cell culture and clinical specimens, whereas the RdRp-P2 assay cross-reacted with SARS-CoV in cell culture. The highly sensitive and specific COVID-19-RdRp/Hel assay may help to improve the laboratory diagnosis of COVID-19. Full Article
en Emergence of a Novel Coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2: Biology and Therapeutic Options [Minireviews] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 The new decade of the 21st century (2020) started with the emergence of a novel coronavirus known as SARS-CoV-2 that caused an epidemic of coronavirus disease (COVID-19) in Wuhan, China. It is the third highly pathogenic and transmissible coronavirus after severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in humans. The source of origin, transmission to humans, and mechanisms associated with the pathogenicity of SARS-CoV-2 are not yet clear, however, its resemblance to SARS-CoV and several other bat coronaviruses was recently confirmed through genome sequencing-related studies. The development of therapeutic strategies is necessary in order to prevent further epidemics and cure infections. In this review, we summarize current information about the emergence, origin, diversity, and epidemiology of three pathogenic coronaviruses with a specific focus on the current outbreak in Wuhan, China. Furthermore, we discuss the clinical features and potential therapeutic options that may be effective against SARS-CoV-2. Full Article
en Multicenter Evaluation of the QIAstat-Dx Respiratory Panel for Detection of Viruses and Bacteria in Nasopharyngeal Swab Specimens [Virology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 The QIAstat-Dx Respiratory Panel (QIAstat-Dx RP) is a multiplex in vitro diagnostic test for the qualitative detection of 20 pathogens directly from nasopharyngeal swab (NPS) specimens. The assay is performed using a simple sample-to-answer platform with results available in approximately 69 min. The pathogens identified are adenovirus, coronavirus 229E, coronavirus HKU1, coronavirus NL63, coronavirus OC43, human metapneumovirus A and B, influenza A, influenza A H1, influenza A H3, influenza A H1N1/2009, influenza B, parainfluenza virus 1, parainfluenza virus 2, parainfluenza virus 3, parainfluenza virus 4, rhinovirus/enterovirus, respiratory syncytial virus A and B, Bordetella pertussis, Chlamydophila pneumoniae, and Mycoplasma pneumoniae. This multicenter evaluation provides data obtained from 1,994 prospectively collected and 310 retrospectively collected (archived) NPS specimens with performance compared to that of the BioFire FilmArray Respiratory Panel, version 1.7. The overall percent agreement between QIAstat-Dx RP and the comparator testing was 99.5%. In the prospective cohort, the QIAstat-Dx RP demonstrated a positive percent agreement of 94.0% or greater for the detection of all but four analytes: coronaviruses 229E, NL63, and OC43 and rhinovirus/enterovirus. The test also demonstrated a negative percent agreement of ≥97.9% for all analytes. The QIAstat-Dx RP is a robust and accurate assay for rapid, comprehensive testing for respiratory pathogens. Full Article
en Fourier Transform Infrared Spectroscopy Is a New Option for Outbreak Investigation: a Retrospective Analysis of an Extended-Spectrum-Beta-Lactamase-Producing Klebsiella pneumoniae Outbreak in a Neonatal Intensive Care Unit [Epidemiology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 The IR Biotyper is a new automated typing system based on Fourier-transform infrared (FT-IR) spectroscopy that gives results within 4 h. We aimed (i) to use the IR Biotyper to retrospectively analyze an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) in a neonatal intensive care unit and to compare results to BOX-PCR and whole-genome sequencing (WGS) results as the gold standard and (ii) to assess how the cutoff values used to define clusters affect the discriminatory power of the IR Biotyper. The sample consisted of 18 isolates from 14 patients. Specimens were analyzed in the IR Biotyper using the default analysis settings, and spectra were analyzed using OPUS 7.5 software. The software contains a feature that automatically proposes a cutoff value to define clusters; the cutoff value defines up to which distance the spectra are considered to be in the same cluster. Based on FT-IR, the outbreak represented 1 dominant clone, 1 secondary clone, and several unrelated clones. FT-IR results, using the cutoff value generated by the accompanying software after 4 replicates, were concordant with WGS for all but 1 isolate. BOX-PCR was underdiscriminatory compared to the other two methods. Using the cutoff value generated after 12 replicates, the results of FT-IR and WGS were completely concordant. The IR Biotyper can achieve the same typeability and discriminatory power as genome-based methods. However, to attain this high performance requires either previous, strain-dependent knowledge about the optimal technical parameters to be used or validation by a second method. Full Article
en Transcriptome reconstruction and functional analysis of eukaryotic marine plankton communities via high-throughput metagenomics and metatranscriptomics [METHOD] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 Large-scale metagenomic and metatranscriptomic data analyses are often restricted by their gene-centric approach, limiting the ability to understand organismal and community biology. De novo assembly of large and mosaic eukaryotic genomes from complex meta-omics data remains a challenging task, especially in comparison with more straightforward bacterial and archaeal systems. Here, we use a transcriptome reconstruction method based on clustering co-abundant genes across a series of metagenomic samples. We investigated the co-abundance patterns of ~37 million eukaryotic unigenes across 365 metagenomic samples collected during the Tara Oceans expeditions to assess the diversity and functional profiles of marine plankton. We identified ~12,000 co-abundant gene groups (CAGs), encompassing ~7 million unigenes, including 924 metagenomics-based transcriptomes (MGTs, CAGs larger than 500 unigenes). We demonstrated the biological validity of the MGT collection by comparing individual MGTs with available references. We identified several key eukaryotic organisms involved in dimethylsulfoniopropionate (DMSP) biosynthesis and catabolism in different oceanic provinces, thus demonstrating the potential of the MGT collection to provide functional insights on eukaryotic plankton. We established the ability of the MGT approach to capture interspecies associations through the analysis of a nitrogen-fixing haptophyte-cyanobacterial symbiotic association. This MGT collection provides a valuable resource for analyses of eukaryotic plankton in the open ocean by giving access to the genomic content and functional potential of many ecologically relevant eukaryotic species. Full Article
en Complete characterization of the human immune cell transcriptome using accurate full-length cDNA sequencing [METHOD] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 The human immune system relies on highly complex and diverse transcripts and the proteins they encode. These include transcripts encoding human leukocyte antigen (HLA) receptors as well as B cell and T cell receptors (BCR and TCR). Determining which alleles an individual possesses for each HLA gene (high-resolution HLA typing) is essential to establish donor–recipient compatibility in organ and bone marrow transplantations. In turn, the repertoires of millions of unique BCR and TCR transcripts in each individual carry a vast amount of health-relevant information. Both short-read RNA-seq-based HLA typing and BCR/TCR repertoire sequencing (AIRR-seq) currently rely on our incomplete knowledge of the genetic diversity at HLA and BCR/TCR loci. Here, we generated over 10,000,000 full-length cDNA sequences at a median accuracy of 97.9% using our nanopore sequencing-based Rolling Circle Amplification to Concatemeric Consensus (R2C2) protocol. We used this data set to (1) show that deep and accurate full-length cDNA sequencing can be used to provide isoform-level transcriptome analysis for more than 9000 loci, (2) generate accurate sequences of HLA alleles, and (3) extract detailed AIRR data for the analysis of the adaptive immune system. The HLA and AIRR analysis approaches we introduce here are untargeted and therefore do not require prior knowledge of the composition or genetic diversity of HLA and BCR/TCR loci. Full Article
en Arabidopsis retrotransposon virus-like particles and their regulation by epigenetically activated small RNA [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 In Arabidopsis, LTR retrotransposons are activated by mutations in the chromatin gene DECREASE in DNA METHYLATION 1 (DDM1), giving rise to 21- to 22-nt epigenetically activated siRNA (easiRNA) that depend on RNA DEPENDENT RNA POLYMERASE 6 (RDR6). We purified virus-like particles (VLPs) from ddm1 and ddm1rdr6 mutants in which genomic RNA is reverse transcribed into complementary DNA. High-throughput short-read and long-read sequencing of VLP DNA (VLP DNA-seq) revealed a comprehensive catalog of active LTR retrotransposons without the need for mapping transposition, as well as independent of genomic copy number. Linear replication intermediates of the functionally intact COPIA element EVADE revealed multiple central polypurine tracts (cPPTs), a feature shared with HIV in which cPPTs promote nuclear localization. For one member of the ATCOPIA52 subfamily (SISYPHUS), cPPT intermediates were not observed, but abundant circular DNA indicated transposon "suicide" by auto-integration within the VLP. easiRNA targeted EVADE genomic RNA, polysome association of GYPSY (ATHILA) subgenomic RNA, and transcription via histone H3 lysine-9 dimethylation. VLP DNA-seq provides a comprehensive landscape of LTR retrotransposons and their control at transcriptional, post-transcriptional, and reverse transcriptional levels. Full Article
en Rapid evolution of piRNA-mediated silencing of an invading transposable element was driven by abundant de novo mutations [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:24-07:00 The regulation of transposable element (TE) activity by small RNAs is a ubiquitous feature of germlines. However, despite the obvious benefits to the host in terms of ensuring the production of viable gametes and maintaining the integrity of the genomes they carry, it remains controversial whether TE regulation evolves adaptively. We examined the emergence and evolutionary dynamics of repressor alleles after P-elements invaded the Drosophila melanogaster genome in the mid-twentieth century. In many animals including Drosophila, repressor alleles are produced by transpositional insertions into piRNA clusters, genomic regions encoding the Piwi-interacting RNAs (piRNAs) that regulate TEs. We discovered that ~94% of recently collected isofemale lines in the Drosophila melanogaster Genetic Reference Panel (DGRP) contain at least one P-element insertion in a piRNA cluster, indicating that repressor alleles are produced by de novo insertion at an exceptional rate. Furthermore, in our sample of approximately 200 genomes, we uncovered no fewer than 80 unique P-element insertion alleles in at least 15 different piRNA clusters. Finally, we observe no footprint of positive selection on P-element insertions in piRNA clusters, suggesting that the rapid evolution of piRNA-mediated repression in D. melanogaster was driven primarily by mutation. Our results reveal for the first time how the unique genetic architecture of piRNA production, in which numerous piRNA clusters can encode regulatory small RNAs upon transpositional insertion, facilitates the nonadaptive rapid evolution of repression. Full Article
en Leveraging mouse chromatin data for heritability enrichment informs common disease architecture and reveals cortical layer contributions to schizophrenia [RESEARCH] By genome.cshlp.org Published On :: 2020-04-27T12:09:23-07:00 Genome-wide association studies have implicated thousands of noncoding variants across common human phenotypes. However, they cannot directly inform the cellular context in which disease-associated variants act. Here, we use open chromatin profiles from discrete mouse cell populations to address this challenge. We applied stratified linkage disequilibrium score regression and evaluated heritability enrichment in 64 genome-wide association studies, emphasizing schizophrenia. We provide evidence that mouse-derived human open chromatin profiles can serve as powerful proxies for difficult to obtain human cell populations, facilitating the illumination of common disease heritability enrichment across an array of human phenotypes. We demonstrate that signatures from discrete subpopulations of cortical excitatory and inhibitory neurons are significantly enriched for schizophrenia heritability with maximal enrichment in cortical layer V excitatory neurons. We also show that differences between schizophrenia and bipolar disorder are concentrated in excitatory neurons in cortical layers II-III, IV, and V, as well as the dentate gyrus. Finally, we leverage these data to fine-map variants in 177 schizophrenia loci nominating variants in 104/177. We integrate these data with transcription factor binding site, chromatin interaction, and validated enhancer data, placing variants in the cellular context where they may modulate risk. Full Article
en Correction: Targeting IDH1 as a Prosenescent Therapy in High-grade Serous Ovarian Cancer By mcr.aacrjournals.org Published On :: 2020-05-04T05:40:21-07:00 Full Article
en A Noncanonical Role of Fructose-1, 6-Bisphosphatase 1 Is Essential for Inhibition of Notch1 in Breast Cancer By mcr.aacrjournals.org Published On :: 2020-05-04T05:40:21-07:00 Breast cancer is a leading cause of death in women worldwide, but the underlying mechanisms of breast tumorigenesis remain unclear. Fructose-1, 6-bisphosphatase 1 (FBP1), a rate-limiting enzyme in gluconeogenesis, was recently shown to be a tumor suppressor in breast cancer. However, the mechanisms of FBP1 as a tumor suppressor in breast cancer remain to be explored. Here we showed that FBP1 bound to Notch1 in breast cancer cells. Moreover, FBP1 enhanced ubiquitination of Notch1, further leading to proteasomal degradation via FBXW7 pathway. In addition, we found that FBP1 significantly repressed the transactivation of Notch1 in breast cancer cells. Functionally, Notch1 was involved in FBP1-mediated tumorigenesis of breast cancer cells in vivo and in vitro. Totally, these findings indicate that FBP1 inhibits breast tumorigenesis by regulating Notch1 pathway, highlighting FBP1 as a potential therapeutic target for breast cancer. Implications: We demonstrate FBP1 as a novel regulator for Notch1 in breast cancer. Full Article
en Complex Rab4-Mediated Regulation of Endosomal Size and EGFR Activation By mcr.aacrjournals.org Published On :: 2020-05-04T05:40:21-07:00 Early sorting endosomes are responsible for the trafficking and function of transferrin receptor (TfR) and EGFR. These receptors play important roles in iron uptake and signaling and are critical for breast cancer development. However, the role of morphology, receptor composition, and signaling of early endosomes in breast cancer remains poorly understood. A novel population of enlarged early endosomes was identified in breast cancer cells and tumor xenografts but not in noncancerous MCF10A cells. Quantitative analysis of endosomal morphology, cargo sorting, EGFR activation, and Rab GTPase regulation was performed using super-resolution and confocal microscopy followed by 3D rendering. MDA-MB-231 breast cancer cells have fewer, but larger EEA1-positive early endosomes compared with MCF10A cells. Live-cell imaging indicated dysregulated cargo sorting, because EGF and Tf traffic together via enlarged endosomes in MDA-MB-231, but not in MCF10A. Large EEA1-positive MDA-MB-231 endosomes exhibited prolonged and increased EGF-induced activation of EGFR upon phosphorylation at tyrosine-1068 (EGFR-p1068). Rab4A overexpression in MCF10A cells produced EEA1-positive enlarged endosomes that displayed prolonged and amplified EGF-induced EGFR-p1068 activation. Knockdown of Rab4A lead to increased endosomal size in MCF10A, but not in MDA-MB-231 cells. Nevertheless, Rab4A knockdown resulted in enhanced EGF-induced activation of EGFR-p1068 in MDA-MB-231 as well as downstream signaling in MCF10A cells. Altogether, this extensive characterization of early endosomes in breast cancer cells has identified a Rab4-modulated enlarged early endosomal compartment as the site of prolonged and increased EGFR activation. Implications: Enlarged early endosomes play a Rab4-modulated role in regulation of EGFR activation in breast cancer cells. Full Article
en Endogenous PAD4 in Breast Cancer Cells Mediates Cancer Extracellular Chromatin Network Formation and Promotes Lung Metastasis By mcr.aacrjournals.org Published On :: 2020-05-04T05:40:21-07:00 Peptidyl arginine deiminase 4 (PAD4/PADI4) is a posttranslational modification enzyme that converts protein arginine or mono-methylarginine to citrulline. The PAD4-mediated hypercitrullination reaction in neutrophils causes the release of nuclear chromatin to form a chromatin network termed neutrophil extracellular traps (NET). NETs were first described as antimicrobial fibers that bind and kill bacteria. However, it is not known whether PAD4 can mediate the release of chromatin DNA into the extracellular space of cancer cells. Here, we report that murine breast cancer 4T1 cells expressing high levels of PADI4 can release cancer extracellular chromatin networks (CECN) in vitro and in vivo. Deletion of Padi4 using CRISPR/Cas9 abolished CECN formation in 4T1 cells. Padi4 deletion from 4T1 cells also reduced the rate of tumor growth in an allograft model, and decreased lung metastasis by 4T1 breast cancers. DNase I treatment, which degrades extracellular DNA including CECNs, also reduced breast to lung metastasis of Padi4 wild-type 4T1 cells in allograft experiments in the Padi4-knockout mice. We further demonstrated that DNase I treatment in this mouse model did not alter circulating tumor cells but decreased metastasis through steps after intravasation. Taken together, our genetic studies show that PAD4 plays a cell autonomous role in cancer metastasis, thus revealing a novel strategy for preventing cancer metastasis by inhibiting cancer cell endogenous PAD4. Implications: This study shows that PADI4 can mediate the formation of CECNs in 4T1 cells, and that endogenous PADI4 plays an essential role in breast cancer lung metastasis. Visual Overview: http://mcr.aacrjournals.org/content/molcanres/18/5/735/F1.large.jpg. Full Article
en Nucleostemin Modulates Outcomes of Hepatocellular Carcinoma via a Tumor Adaptive Mechanism to Genomic Stress By mcr.aacrjournals.org Published On :: 2020-05-04T05:40:21-07:00 Hepatocellular carcinomas (HCC) are adapted to survive extreme genomic stress conditions imposed by hyperactive DNA replication and genotoxic drug treatment. The underlying mechanisms remain unclear, but may involve intensified DNA damage response/repair programs. Here, we investigate a new role of nucleostemin (NS) in allowing HCC to survive its own malignancy, as NS was previously shown to promote liver regeneration via a damage repair mechanism. We first established that a higher NS transcript level correlates with high-HCC grades and poor prognostic signatures, and is an independent predictor of shorter overall and progression-free survival specifically for HCC and kidney cancer but not for others. Immunostaining confirmed that NS is most abundantly expressed in high-grade and metastatic HCCs. Genome-wide analyses revealed that NS is coenriched with MYC target and homologous recombination (HR) repair genes in human HCC samples and functionally intersects with those involved in replication stress response and HR repair in yeasts. In support, NS-high HCCs are more reliant on the replicative/oxidative stress response pathways, whereas NS-low HCCs depend more on the mTOR pathway. Perturbation studies showed NS function in protecting human HCC cells from replication- and drug-induced DNA damage. Notably, NS depletion in HCC cells increases the amounts of physical DNA damage and cytosolic double-stranded DNA, leading to a reactive increase of cytokines and PD-L1. This study shows that NS provides an essential mechanism for HCC to adapt to high genomic stress for oncogenic maintenance and propagation. NS deficiency sensitizes HCC cells to chemotherapy but also triggers tumor immune responses. Implications: HCC employs a novel, nucleostemin (NS)-mediated-mediated adaptive mechanism to survive high genomic stress conditions, a deficiency of which sensitizes HCC cells to chemotherapy but also triggers tumor immune responses. Full Article